Joseph w



(No Model.) 7

J. W. LARISH.

MULTIPLE TELEGBAPHY.

No. 257,499. Patented Ma 9,1882.

UNITED STATES PATENT OFFICE.

JOSEPH W. LARISH, OF BUFFALO,'N. Y., ASSIGNOR OF SIX-TENTHS TO JAMES W. TILLINGHAST AND FRANK KITTON, BOTH OF SAME PLACE.

MULTIPLE TELEG'RAPHY.

SPECIFICATIONforming part of Letters Patent No. 257,499, dated May 9, 1882.

Application filed January 20, 1882. (No model.) i

To all whom it may concern: 7

Be it known that I, J osEPI-I W. LARISl-I, acitizen of the United States, residing at Buffalo, in the county of Eric and State of New York, have made certain Improvements in Multiple Telegraphy, of which the following is a specification.

The object of this invention is to simplify multiple telegraphy, more especially the working of the duplex system.

The main improvementconsists in dispensing with the use of condensers entirely and substituting therefor two devices, as follows: first, an electro-ma-gnetic shunt for overcom- 1 ing static charge and discharge; second, a device consisting of an improved transmitter, arranged as hereinafter described, whereby the home battery is made to overcome extra-current effects on breaking the battery-circuit at the home station. These two devices are combined for the purpose of preventing mutilated signals at the home station, and the arrange ment and operation of the devices separately and as a whole is hereinafter fully explained.

5 In the drawings, Figure 1 is a diagram of the whole, including lines, instruments, 850.;

Fig. 2, a side elevation of the improved transmitter.

A represents the battery; 13, the transmit- 0 ter; D, an electro-magnet used as a shunt.

' E is a rheostat forming part of the artificial line common to all duplex instruments.

It is another rheostat in the extra circuit, which circuit is for the purpose of overcoming 5 extra-current effects due to extra or induced currents on long circuits, as hereinafter described.

F is a repeating-soumler, which closes the circuit on the upstroke.

K is the key placed in the local circuit, which operates the transmitter and the repeatingsounder.

M is a differential relay.

The operation ofthe whole is as follows: 5 The current from the battery A passes to the transmitter B at a, thence through the setscrew a and spring a,which is insulated from the lever 12, to the point C, where the current divides, one part passing through the differential magnet M to the main line N, the other part passing through said magnet and the electromagnetic shunt D, through the rheostat E, to-carth at G. The transmitter B and repeating-sounder 1 are operated by a local circuit, 0, broken by the key K. When the circuit 0 is closed at K the currentfrom battery A passes through at a a a, and through the magnets to the main line, through the magnets M and shunt D, to theartificial line, and through the rhcostat E to earth. In this mannor the shunt D receives a portion of the current, which causes an induced current from the magnet, and the induced current so formed being of same strength and polarity, and going through artificial side of relay M in opposite directions around cores to the current through true line side of relay M, thereby neutralizing andovercoming static charge,consequentl yprevcntin g at'alse signal on relay from that source. hen the local current is broken at I: the lever 1) of the transn'iitter is released, breaking the main-line current from A ate a", simultancously forming a circuit through the spring a and lever 7), at b, post b to earth G. \Vhcn at the home station a momentary return-curthe line is thus thrown from battery to earth rent-technicallyknownasstaticdischargeis found to be coming through the true line side of home relay M, which is met and overcome by the reaction of shunt D in sending a cur- 8o rent of equal strength through the other or artificial halt of relay M, thereby neutralizing and overcoming static discharge, so that no false signal is produced. At same time, however, with static discharge an extra current excited on true line by home battery is encountered of sufficient strength (varying in ac cordance with conditions of line) to produce a false signal on relay M. This is met and overcome by means ofthc second device, whereby 0 with the aid of the improved transmitter a momentary charge from the home battery is thrown through artificial side of relay M in.opposite directions (on the core) to extra current, and of sufficient. strength (regulated by resist- 5 once R) to neutralize and overcome its effect, thereby preventing false or mutilated signals at home station. To illustrate: When the bat tery is put to the line an induced current opposite to battery-current is produced on true line side of relay M with aforce, say, of twenty five. At same'moment an induced current is excited in shunt D (which is of adjustable strength) with a force of twenty-five, and this current, going through relay M in an opposite direction to current or static charge on true line side, serves toneutralize and overcomeit. Consequently no effect is produced on the home relay M,and the signals are therefore not mutilated. The second device acts as follows: When th line is thrown from battery to earth an extra current excited by home battery passes to earth through home relayM. This current of course varies in strength with the length and conditions of the line. Let us say on a line of fi've hundred miles the extra current has a force offifty. ltis therefore found necessary to throw a current (by means of the second device) having a force of fifty through artificial side of relay M, and in an opposite direction in relay to extra current from true line, whereby the effect of extra current on relay is neutralized and overcome, so that no mutilations of signals are felt at home station. At the same time the lever of the repeating sounder F is released.

, require it, thus doing away with condensers.

insulated from frame h at p.

Immediately thereafter contact is formed between the points atf, but is no sooner formed than broken by raising the insulated spring 3 from the post 1). At the instant of contacta current from the battery A passes through the points f s p and the lever ot' the repeatingsounder F, through the rhcostat R, to the artificial line, thence through difi'erential relay M, and through shunt D, point 0, a, b, 1), D to earth. A sufficient portion of this momentary current (regulated by resistance R) passes through the magnet M to neutralize the efi'ect of the extra or induced current from true line on long circuits where the conditions thereof Upon closing the local circuit the circuit through repeating-sounder F for the current from A is broken by the repeating-sounder beforecontact is'made atf, s, and p.

The following is a description of the transmitter B, (see Fig. 2:) a is a metallic frame on a wooden base. a is an adjustable screw set in frame a. a is a spring; I), a lever, with a metallic fulcrum, I), in the center, resting on same base as a. h is a metallic frame resting on same base with n and b f is a small metallic arm extending from lever b, and insulated from it at f. p is an adjustable screw 8 is a metallic spring insulated from h at s. (l is an adjustable screw set in h. 0 is an electro-magnet. Spring-a is insulated from b at a. w is an arm. attached to lever 12. m is a coil-spring fastened torarm w, and held by an adjustable screw; and nut to frame h. b is a soft-iron bar actedupon by the magnet 0.

The operation of this transmitter in connection with the system. has been hereinbefore fully described. The novelty of its construction consists in putting a momentary current through points f, s, and 9 after the lever b has left its point of rest at the bottom, and. breaking the connection again at s before lever 1) comes to a rest at screw d on the upstroke, so that a charge from batteryAis thrown through these points f, s, and 9, only for an instant, while lever b is in the center of its stroke between point and end of screw 07.

The construction of the other parts of this deviceis similar to transmitters used by the \Vestern Union and other telegraph companies.

L represents the local receiving-sounder and the local current 0, by which it is operated in connection with the differential relay M.

- 1. The combination of the battery A, transmitter B, differential relay M, clectro-magnetic shunt D, rheostats E and 1t, repeatingsounder F, circuit-breaker K, and the local circuits c and c, and the metallic conductor (wire or otherwise) connecting battery A with metallic armfof transmitter B, the metallic conductor connecting adjustable screw 1) with armature of repeating-sounder F, metallic conductor connecting repeating-sounder F with artificial line through adjustable resistance R, all arranged and operating substantially in the manner and for the purpose specified.

2. The combination of elements or parts in a'system of multiple telegraphy, consisting of a metallic connection between battery A and pointfon transmitter B, a like connection between set-screwy on transmitter and armature on repeating-sounder F, a like connection be.- tween set-screw of frame of repeating-sounder F, through resistance R, to artificial line between rhcostat E and differential .relay M, a like connection from rhcostat E, or any pointbetween it and ditt'erential relay M, through electromagnetic shunt D, to point of division 0, all combined and operating as described, and in combination with the local circuit a c c, with circuit-breaker K, whereby repeatingsounder F is worked in same circuit with transmitter B, as specified.

3. An improved transmitter, B, one part constructed substantially as those in common use, with contiunity-preserving points, a lever with fulcrum in the center, said lever operated by an electro-magnet, and in combination with circuit-tweaking or contact points at the opposite end to the continuity-preserving points, consisting of a metallic arm,f, extending from lever band insulated from it atf, an adjustable screw, 1), insulated from frame it at p, and a metal spring, 8, insulated from h at s, all arranged and operating in this. system of multiple telegraphy substantially as described.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

' JOSEPH XV. LARISH.

Witnesses:

J. R. DRAKE, J. W. TILLINGHAST. 

